Wire-drawing apparatus



March 8, 1966 R. H. OTT

WIRE-DRAWING APPARATUS Filed April 16, 1964 IIIIL] Fig. 2

INVENTOR.

RICHARD H. OTT

Fig. 3

United States Patent 3,238,758 WIRE-DRAWING APPARATUS Richard H. Ott, Muskegon, Mich, assignor to Anaconda Wire and Cable Company, a corporation of Delaware Filed Apr. 16, 1964, Ser. No. 360,189 2 Claims. (Cl. 72-279) My invention relates to apparatus for wire drawing and particularly to an improved wire-drawing roll.

In known types of wire drawing apparatus the wire is passed through a series of hard surfaced dies each of which reduces it a small proportion of the total reduction required. Traction must be applied to the wire leaving each successive die and this is accomplished by means of drawing blocks or capstans over which the wire is passed prior to entering the next smaller die. The size of the capstans increases in steps proportional to the decrease in area and it would be theoretically possible to arrange the dies in an extended straight line with capstans in between. This, however, is not commercially feasible because of the space required and the cost of driving capstans at a uniform speed when they are widely separated from each other. For this reason stepped type wiredrawing machines of compact construction have long been used. In such machines a plurality of stepped capstans of increasing diameter are mounted on a single shaft to pull the wire through a succession of dies which are mounted in lines tangential to the capstan surfaces. A matching series of guide rolls or capstans are mounted on a shaft to pay the wire into the dies. Thus, after it leaves a pulling capstan the wire is returned to the next larger size guide roll to be payed into the next smaller die. The smaller guide roll is, however, in a different position on the shaft, which means that the wire is returned to the guide roll at an angle across its surface.

It is highly desirable that wire paying into a drawing die should follow the axis of the die and not change direction, even slightly, to pass through the die since this will create uneven pressure at the entrance to the die and cause uneven wear. The wire should, therefore, pay off from a point on the guide roll that is in a straight line with the die axis. It has been known to make the guide rolls slightly conical, that is, to taper them slightly down to a shoulder. This had the disadvantage that the wire would abrade against the shoulder or flange, and since the surface on which it was riding was not strictly cylindrical, slack could form in the Wire at the small diameter of the cone, resulting in a certain jerkiness of feed.

By my invention I propose to construct a wire-drawing apparatus wherein the wire is fed squarely into the dies.

'1 further propose to construct an apparatus wherein the wire is payed smoothly and free from danger of abrasion.

For use in the apparatus of my invention I have invented a roll comprising a band having a smooth untapered cylindrical surface and an expanded portion extending unbrokenly in a smooth curve from this surface, with the curve being tangent to the surface. Preferably the expanded portion is about equal in extent to the cylindrical surface.

My invention involves an improvement in wire-drawing apparatus of the stepped-cone type comprising a frame rotatably mounting two parallel shafts with a plurality of stepped upstream rolls on one shaft and a like plurality of stepped downstream rolls on the other shaft. The apparatus includes means for driving at least one of these shafts. In using the terms upstream rolls and downstream rolls I mean to refer to r-olls that are upstream and downstream respectively of some wire-drawing die. As shall hereinafter be more fully explained my invention also has application to machines that draw the wire moving in both directions so that a single roll serves both as a capstan, pulling wire from a first die, and as an idler roll,

paying it into a second die. Such a roll would be considered a downstream roll with reference to the first die and an upstream roll with reference to the second die. The apparatus also comprises at least two wire-drawing dies mounted to draw wire paying from the upstream rolls on the first shaft, through the dies, and onto downstream rolls on the second shaft. Each upstream roll receives wire obliquely from a downstream roll and my improvement comprises the structure in which the rolls passing wires into the dies comprise bands with smooth, untapered cylindrical surfaces and expanded portions extending unbrokenly in smooth curves from these surfaces. The curve of the expanded portion meets the cylindrical surface in a circumferential line at which the curve is tangent to the surface and I prefer to arrange the dies so that the die axes are in a line tangential to the upstream roll surface at the above-mentioned circumferential line.

A more thorough understanding of my invention can be gained from the appended drawing.

In the drawing:

FIGURE 1 shows a partial section of a guide roll made to my invention.

FIGURE 2 shows a front view of the roll of FIGURE 1.

FIGURE 3 shows a plan view of an apparatus compris ing the improvement of my invention.

Referring first to FIGURE 3 a wire drawing apparatus, indicated generally by the numeral 10 has a box-like frame 11 with a front wall 12 and a rear wall 13. A shaft 14 passes through the Wall 12 and is supported by bearings 16, 17. A parallel shaft 18 is spaced from the shaft 14, supported in bearing 19, 20. Six rolls 21-26 are mounted on'the shaft 14 and six matching rolls 27-32 are mounted on the shaft 18 on the portion of the shafts that project out of the frame 11 through the wall 12. The rolls 21-26, 27-32 are mounted between flanges 15 and are stepped. That is, they are of progressively larger diameter on the shafts with the smaller rolls nearer the wall 12. Although my invention has been very successfully applied to apparatus with stepped rolls of the type shown in FIGURE 3 it will be understood that it is not limited to apparatus with this arrangement, particularly it will vbe understood that my invention is useful for apparatus wherein the rolls are stepped so that the smaller rolls are at the end and the largest ones closer to the frame. Between the shafts 14, 18, there is mounted a bracket 33 which fixedly supports six wire-drawing dies 34-39. My invention has particular application to apparatus wherein the dies are fixedly mounted and it eliminates the need for pivotal or slide mountings. A wire 41 is passed around the rolls and through the dies in such a manner that, with respect to the dies 34-39 the rolls 21-26 are upstream and the rolls 27-32 are downstream. The shaft 18 is driven by a motor 42 and belt 43 with the result that the rolls 27-32 act as capstans, pulling the wire 41 through the dies. The novel shape of the rolls 21-26 and preferably also the rolls 27-32 can best be seen in FIGURES l and 2, showing the roll 24.- This is comprised of a band or rim 44 with a cylindrical surface 46 and an expanded portion 47. The portion 47 rises from the surface 46 in a smooth curve 48 that meets the surface 46 in a circumferential line 49 at which the curve is tangent to the surface. Referring back to FIGURE 3 it will be seen that the wire 41 passes onto the roll 24 from the downstream roll 29 at an oblique angle a and thence it passes through the die 37 onto the roll 30 which acts as a capstan. To cause even wear on the die 37 it is highly desirable that the wire entering the die should be in line with the die axis. For this reason I have lined the axis of the die 37 tangentially to the circumferential line 49. The dies 34, 35, 36, 38, 39 are similarly lined up with reference to the respective rolls 21, 22, 23, 25, 26. Any tendency of the wire entering the dies, such as the die 37, to enter obliquely due to the off-axis angle of approach from the last downstream capstan is counteracted by the expanded portion 47 of the roll. Although it is of prime importance to use the rolls of my invention upstream of the dies, I have found that it is also advantageous to use them for the downstream capstans 27-32 to assure proper centering of the wire on the capstans. Although, in the apparatus 10, only the shaft 18 is driven, my invention envisions driving the shaft 14, as well, either to produce back tension in the wire or to use the rolls 2126 as capstans and pass the wires through an additional set of dies in the return passage. I have shown each of the pair of rolls upstream and downstream of the same die to be equal in size. This means, of course, that the shaft 14 will be rotated at a slower speed than the shaft 18. It will be readily understood that other arrangements, such as operating the shafts at the same speed but using larger rolls on the downstream side, might also be employed within the scope of my invention.

I have invented a new and useful apparatus for wiredrawing for which I desire an award of Letters Patent.

1 claim: 1. In a wire-drawing apparatus of the stepped-cone type comprising:

a frame rotatably mounting two parallel shafts, a plurality of stepped upstream rolls on one of said shafts, a like plurality of stepped downstream rolls on the other of said shafts, at least two wire-drawing dies having central axes mounted to draw a wire paying from the upstream rolls into said dies and onto downstream rolls, said upstream rolls paying into said dies receiving wire obliquely from one of said downstream rolls, and means driving at least one of said shafts, the improvement comprising:

(A) at least one of said upstream rolls comprising:

(a) a band having a smooth, untapered cylindrical surface, and

4 (b) an expanded portion extending unbrokenly in a smooth curve from said surface, said wire passing from said surface into one of said dies along the line of its axis.

2. In a wire drawing apparatus of the stepped-cone type comprising:

a frame rotatably mounting two parallel shafts,

a plurality of stepped upstream rolls on one of said shafts,

a like plurality of stepped downstream rolls on the other of said shafts,

at least two Wire drawing dies, having central axes, mounted to draw a wire paying from said upstream rolls into said dies and onto said downstream rolls, said upstream rolls paying into said dies receiving wire obliquely from one of said downstream rolls,

means driving at least one of said shafts,

the improvement comprising:

(A) at least one of said upstream rolls comprising:

(a) a band having a smooth, untapered, cylindrical surface and (b) an expanded portion extending unbrokenly in a smooth curve from a circumferential line on said surface, said curve being tangent to said surface at said line,

(B) the axis of the die directly downstream of the roll having said surface being tangent to said surface in the plane of said line, whereby said wire passing obliquely onto said surface will leave said surface and enter one of said dies in the line of its axis.

References Cited by the Examiner UNITED STATES PATENTS 1,344,568 6/1920 Sullivan 20513 2,024,768 12/1935 Johnson 205-l3 2,024,769 12/1935 Johnson 205-13 CHARLES W. LANHAM, Primary Examiner. 

1. IN A WIRE-DRAWING APPARATUS OF THE STEPPED-CONE TYPE COMPRISING: A FRAME ROTATABLY MOUNTING TWO PARALLEL SHAFTS, A PLURALITY OF STEPPED UPSTREAM ROLLS ON ONE OF SAID SHAFTS, A LIKE PLURALITY OF STEPPED DOWNSTREAM ROLLS ON THE OTHER OF SAID SHAFTS, AT LEAST TWO WIRE-DRAWING DIES HAVING CENTRAL AXES MOUNTED TO DRAW A WIRE PAYING FROM THE UPSTREAM ROLLS INTO SAID DIES AND ONTO DOWNSTREAM ROLLS, SAID UPSTREAM ROLLS PAYING INTO SAID DIES RECEIVING WIRE OBLIQUELY FROM ONE OF SAID DOWNSTREAM ROLLS, AND MEANS DRIVING AT LEAST ONE OF SAID SHAFTS, THE IMPROVEMENT COMPRISING: (A) AT LEAST ONE OF SAID UPSTREAM ROLLS COMPRISING: (A) A BAND HAVING A SMOOTH, UNTAPERED CYLINDRICAL SURFACE, AND (B) AN EXPANDED PORTION EXTENDING UNBROKENLY IN A SMOOTH CURVE FROM SAID SURFACE, SAID WIRE PASSING FROM SAID SURFACE INTO ONE OF SAID DIES ALONG THE LINE OF ITS AXIS. 